from test import test_support import types import unittest class FuncAttrsTest(unittest.TestCase): def setUp(self): class F: def a(self): pass def b(): return 3 self.f = F self.fi = F() self.b = b def cannot_set_attr(self, obj, name, value, exceptions): # Helper method for other tests. try: setattr(obj, name, value) except exceptions: pass else: self.fail("shouldn't be able to set %s to %r" % (name, value)) try: delattr(obj, name) except exceptions: pass else: self.fail("shouldn't be able to del %s" % name) class FunctionPropertiesTest(FuncAttrsTest): # Include the external setUp method that is common to all tests def test_module(self): self.assertEqual(self.b.__module__, __name__) def test_dir_includes_correct_attrs(self): self.b.known_attr = 7 self.assertIn('known_attr', dir(self.b), "set attributes not in dir listing of method") # Test on underlying function object of method self.f.a.im_func.known_attr = 7 self.assertIn('known_attr', dir(self.f.a), "set attribute on unbound method implementation in " "class not in dir") self.assertIn('known_attr', dir(self.fi.a), "set attribute on unbound method implementations, " "should show up in next dir") def test_duplicate_function_equality(self): # Body of `duplicate' is the exact same as self.b def duplicate(): 'my docstring' return 3 self.assertNotEqual(self.b, duplicate) def test_copying_func_code(self): def test(): pass self.assertEqual(test(), None) test.func_code = self.b.func_code self.assertEqual(test(), 3) # self.b always returns 3, arbitrarily def test_func_globals(self): self.assertIs(self.b.func_globals, globals()) self.cannot_set_attr(self.b, 'func_globals', 2, TypeError) def test_func_closure(self): a = 12 def f(): print a c = f.func_closure self.assertIsInstance(c, tuple) self.assertEqual(len(c), 1) # don't have a type object handy self.assertEqual(c[0].__class__.__name__, "cell") self.cannot_set_attr(f, "func_closure", c, TypeError) def test_empty_cell(self): def f(): print a try: f.func_closure[0].cell_contents except ValueError: pass else: self.fail("shouldn't be able to read an empty cell") a = 12 def test_func_name(self): self.assertEqual(self.b.__name__, 'b') self.assertEqual(self.b.func_name, 'b') self.b.__name__ = 'c' self.assertEqual(self.b.__name__, 'c') self.assertEqual(self.b.func_name, 'c') self.b.func_name = 'd' self.assertEqual(self.b.__name__, 'd') self.assertEqual(self.b.func_name, 'd') # __name__ and func_name must be a string self.cannot_set_attr(self.b, '__name__', 7, TypeError) self.cannot_set_attr(self.b, 'func_name', 7, TypeError) # __name__ must be available when in restricted mode. Exec will raise # AttributeError if __name__ is not available on f. s = """def f(): pass\nf.__name__""" exec s in {'__builtins__': {}} # Test on methods, too self.assertEqual(self.f.a.__name__, 'a') self.assertEqual(self.fi.a.__name__, 'a') self.cannot_set_attr(self.f.a, "__name__", 'a', AttributeError) self.cannot_set_attr(self.fi.a, "__name__", 'a', AttributeError) def test_func_code(self): num_one, num_two = 7, 8 def a(): pass def b(): return 12 def c(): return num_one def d(): return num_two def e(): return num_one, num_two for func in [a, b, c, d, e]: self.assertEqual(type(func.func_code), types.CodeType) self.assertEqual(c(), 7) self.assertEqual(d(), 8) d.func_code = c.func_code self.assertEqual(c.func_code, d.func_code) self.assertEqual(c(), 7) # self.assertEqual(d(), 7) try: b.func_code = c.func_code except ValueError: pass else: self.fail("func_code with different numbers of free vars should " "not be possible") try: e.func_code = d.func_code except ValueError: pass else: self.fail("func_code with different numbers of free vars should " "not be possible") def test_blank_func_defaults(self): self.assertEqual(self.b.func_defaults, None) del self.b.func_defaults self.assertEqual(self.b.func_defaults, None) def test_func_default_args(self): def first_func(a, b): return a+b def second_func(a=1, b=2): return a+b self.assertEqual(first_func.func_defaults, None) self.assertEqual(second_func.func_defaults, (1, 2)) first_func.func_defaults = (1, 2) self.assertEqual(first_func.func_defaults, (1, 2)) self.assertEqual(first_func(), 3) self.assertEqual(first_func(3), 5) self.assertEqual(first_func(3, 5), 8) del second_func.func_defaults self.assertEqual(second_func.func_defaults, None) try: second_func() except TypeError: pass else: self.fail("func_defaults does not update; deleting it does not " "remove requirement") class InstancemethodAttrTest(FuncAttrsTest): def test_im_class(self): self.assertEqual(self.f.a.im_class, self.f) self.assertEqual(self.fi.a.im_class, self.f) self.cannot_set_attr(self.f.a, "im_class", self.f, TypeError) self.cannot_set_attr(self.fi.a, "im_class", self.f, TypeError) def test_im_func(self): self.f.b = self.b self.assertEqual(self.f.b.im_func, self.b) self.assertEqual(self.fi.b.im_func, self.b) self.cannot_set_attr(self.f.b, "im_func", self.b, TypeError) self.cannot_set_attr(self.fi.b, "im_func", self.b, TypeError) def test_im_self(self): self.assertEqual(self.f.a.im_self, None) self.assertEqual(self.fi.a.im_self, self.fi) self.cannot_set_attr(self.f.a, "im_self", None, TypeError) self.cannot_set_attr(self.fi.a, "im_self", self.fi, TypeError) def test_im_func_non_method(self): # Behavior should be the same when a method is added via an attr # assignment self.f.id = types.MethodType(id, None, self.f) self.assertEqual(self.fi.id(), id(self.fi)) self.assertNotEqual(self.fi.id(), id(self.f)) # Test usage try: self.f.id.unknown_attr except AttributeError: pass else: self.fail("using unknown attributes should raise AttributeError") # Test assignment and deletion self.cannot_set_attr(self.f.id, 'unknown_attr', 2, AttributeError) self.cannot_set_attr(self.fi.id, 'unknown_attr', 2, AttributeError) def test_implicit_method_properties(self): self.f.a.im_func.known_attr = 7 self.assertEqual(self.f.a.known_attr, 7) self.assertEqual(self.fi.a.known_attr, 7) class ArbitraryFunctionAttrTest(FuncAttrsTest): def test_set_attr(self): # setting attributes only works on function objects self.b.known_attr = 7 self.assertEqual(self.b.known_attr, 7) for func in [self.f.a, self.fi.a]: try: func.known_attr = 7 except AttributeError: pass else: self.fail("setting attributes on methods should raise error") def test_delete_unknown_attr(self): try: del self.b.unknown_attr except AttributeError: pass else: self.fail("deleting unknown attribute should raise TypeError") def test_setting_attrs_duplicates(self): try: self.f.a.klass = self.f except AttributeError: pass else: self.fail("setting arbitrary attribute in unbound function " " should raise AttributeError") self.f.a.im_func.klass = self.f for method in [self.f.a, self.fi.a, self.fi.a.im_func]: self.assertEqual(method.klass, self.f) def test_unset_attr(self): for func in [self.b, self.f.a, self.fi.a]: try: func.non_existent_attr except AttributeError: pass else: self.fail("using unknown attributes should raise " "AttributeError") class FunctionDictsTest(FuncAttrsTest): def test_setting_dict_to_invalid(self): self.cannot_set_attr(self.b, '__dict__', None, TypeError) self.cannot_set_attr(self.b, 'func_dict', None, TypeError) from UserDict import UserDict d = UserDict({'known_attr': 7}) self.cannot_set_attr(self.f.a.im_func, '__dict__', d, TypeError) self.cannot_set_attr(self.fi.a.im_func, '__dict__', d, TypeError) def test_setting_dict_to_valid(self): d = {'known_attr': 7} self.b.__dict__ = d # Setting dict is only possible on the underlying function objects self.f.a.im_func.__dict__ = d # Test assignment self.assertIs(d, self.b.__dict__) self.assertIs(d, self.b.func_dict) # ... and on all the different ways of referencing the method's func self.assertIs(d, self.f.a.im_func.__dict__) self.assertIs(d, self.f.a.__dict__) self.assertIs(d, self.fi.a.im_func.__dict__) self.assertIs(d, self.fi.a.__dict__) # Test value self.assertEqual(self.b.known_attr, 7) self.assertEqual(self.b.__dict__['known_attr'], 7) self.assertEqual(self.b.func_dict['known_attr'], 7) # ... and again, on all the different method's names self.assertEqual(self.f.a.im_func.known_attr, 7) self.assertEqual(self.f.a.known_attr, 7) self.assertEqual(self.fi.a.im_func.known_attr, 7) self.assertEqual(self.fi.a.known_attr, 7) def test_delete_func_dict(self): try: del self.b.__dict__ except TypeError: pass else: self.fail("deleting function dictionary should raise TypeError") try: del self.b.func_dict except TypeError: pass else: self.fail("deleting function dictionary should raise TypeError") def test_unassigned_dict(self): self.assertEqual(self.b.__dict__, {}) def test_func_as_dict_key(self): value = "Some string" d = {} d[self.b] = value self.assertEqual(d[self.b], value) class FunctionDocstringTest(FuncAttrsTest): def test_set_docstring_attr(self): self.assertEqual(self.b.__doc__, None) self.assertEqual(self.b.func_doc, None) docstr = "A test method that does nothing" self.b.__doc__ = self.f.a.im_func.__doc__ = docstr self.assertEqual(self.b.__doc__, docstr) self.assertEqual(self.b.func_doc, docstr) self.assertEqual(self.f.a.__doc__, docstr) self.assertEqual(self.fi.a.__doc__, docstr) self.cannot_set_attr(self.f.a, "__doc__", docstr, AttributeError) self.cannot_set_attr(self.fi.a, "__doc__", docstr, AttributeError) def test_delete_docstring(self): self.b.__doc__ = "The docstring" del self.b.__doc__ self.assertEqual(self.b.__doc__, None) self.assertEqual(self.b.func_doc, None) self.b.func_doc = "The docstring" del self.b.func_doc self.assertEqual(self.b.__doc__, None) self.assertEqual(self.b.func_doc, None) class StaticMethodAttrsTest(unittest.TestCase): def test_func_attribute(self): def f(): pass c = classmethod(f) self.assertTrue(c.__func__ is f) s = staticmethod(f) self.assertTrue(s.__func__ is f) def test_main(): test_support.run_unittest(FunctionPropertiesTest, InstancemethodAttrTest, ArbitraryFunctionAttrTest, FunctionDictsTest, FunctionDocstringTest, StaticMethodAttrsTest) if __name__ == "__main__": test_main()